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Prosthetics Modification for Pain Relief of Pressure Points

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Working on this for a while now but I have made some progress that I'd like to share. Not finished because the hacked solution still causes some pain, but this is helping my cousin Zaid with the pain that his prosthetic is giving him.

While in Iraq last April I came across my cousin Zaid. Zaid's an awesome guy with an awesome family with a horrible problem. He's diabetic. Normally that wouldn't be too much a cause for concern in the west. But in Iraq and especially during the 13 year long sanctions he was unable to get appropriate treatment. One of the consequences of not having appropriate car for a diabetic is the atrophy of your extremities. He's been losing toes and now has lost the lower half of his left leg.

Being a hacker and problem solver and newly equipped with 123D Catch I thought I could take a scan of Zaid's leg and bring it back to the states to help with the creation of a 3d printed better fitting prosthetic. Creating a catch of a person's flesh is a challenge so I came up with a solution to draw feature points on his stump as a way of doing point matching.

The files for his leg are in the files section of this photo instructable. Here is a fly around of the 3d data of his leg:

Zaid was experiencing pain at insertion point of his prosthetic. And although I initially thought that making a better fitting 3d printed prosthetic would help, a few months after I came home from Iraq I met Joel Sadler  at a hackathon here in SF. He's helped design a 20$ knee joint and other awesome stuff at Stanford. After describing Zaid's problem he suggested that an exoskeleton which distributes the weight off of the prosthetics insertion point to the rest of his leg would be a better solution. I returned to the states and the next time I returned to Baghdad I brought a knee brace with me.

The idea was that if we could tie the brace tightly enough around the prosthetic, the metal bar that goes through the brace would help distribute the weight to the top of the brace attached to his thigh. I was able to prototype this project the last time I was there with Mujtaba from the Iraqi hackerspce Fikra Space. It didn't remove all the pain from the pressure point on his leg, but it did help. It appears that the addition of a more natural body shaped insertion point would help relieve the rest of the pain. I'd also like to be able to drill the prosthetic into the leg brace but didn't want to damage a 1,200$ prosthetic, even if it doesn't work that well. 

Here's to hack DIY medical care and the future of DIY problem solving. I think that the leg brace technique can help other amputees who have very little of their leg remaining with their pressure pain. I believe the Biomechatronics group at the Media Lab is working on a method which addresses the body forming 3d modeling and molding aspect of the prosthetic and I'm very interested in checking it out.

It's also really exciting to see more open source, 3d printed, and DIY prosthetics projects popping up. Democratized health care. I bet the regulators are concerned ;). Check out this 3D printed robotic hand kickstarter, the OpenExo, Robohand's complete set of mechanical prosthetic fingers on thingiverse and also the Open Source Prosthetics Movement.

Any suggestions, please add them to the comments! This is a GEMSI / Autodesk funded project. The Global Entrepreneurship & Makerspace Initiative is a program of the School Factory and we work on globalizing DIY, open and hackerspace culture. 

Double hugs!
+BG
tytower1 month ago

OK so no one says thank you there . I'll just continue and give some further help in the hope that cousin Zaid gets this from someone .

The blisters I see are caused not by pressure but by friction. Pressure sores wear the skin away. Friction burns are from rubbing . Too much movement of the stump in the socket is the likely cause either up and down pumping or slewing sideways left right or forward back. The cure is to get the leg held in tighter . This is usually caused by shrinking at first until the leg settles at its eventual shrunken state and then from weight change up and down. The fix is to use an old stump sock and pull it over the rubber liner then press the liner back in . This can be done with as many as 4 socks over the outside gradually to allow the rubber cup to shrink down evenly. To test how many are needed just wera 2 or 3 extra socks and pull the leg on and try it for half an hour .

Blisters should be popped with a pin heated in a fire so the fluid gets away at night . Its always going to be sore so get used to it now . Learn to recognise the bad things though like slop from weight loss and squashing from weight gain . With loss you sink further into the socket . with gain you ride higher. There is a right place for it to sit and that keeps your hips level and pressure on the patella properly. Its an art and not all know it . It may be that whoever made the leg didn't know what they were doing . Thats quite common. Place a small pea of plasticine in the bottom of the socket then walk on it for 5 minutes . You should not mark the pea or very little. If its squashed you are too deep in.

If you get rashes ,fungi sores etc get a weak solution of copper sulphate and wipe it at night after your wash. Alternate this with a weak solution of bicarbonate of soda Its very moist and hot in there and there should not be any air flow or the leg is too loose. Consequently its an ideal home for bugs so also remove and wash the rubber liner properly and the inside of the socket to remove your weepings.

If its sitting right when you first take it off you will be red just below the kneecap for a few minutes and that's good . You may find you need to use car repair bog to build up the point behind the knee at the top lip to push the leg forward onto the patella. sand it off smooth . Try to ensure you have enough room to bend without trapping skin folds behind the knee as they will swell and become sore and take a long while to go away. The type of leg that locks at the side of the knee is sometimes problematic. Ask for one with a leather strap above the knee next time to try. It will give less problems but the skin has to harden under the strap too.

That said I am not a Doctor and have no idea what extra problems being a Diabetic may cause .

tytower1 month ago

No wonder he has pressure sores!

tytower1 month ago

I had not looked at the video . You are way off with your marks . No pressure must be taken on the end of the stump nor on the sides . It won't work. The pressure is taken on the pattela tendon which is half way between the top of the knee and your top line ,just exactly under the knee cap center. Thumbs press in there when casting and fingers behind the bent knee as the cast goes off . Feel for this point on your own leg. It is between the bottom of the knee cap and the hard bone you feel .

tytower1 month ago

There is a tried and tested method for doing this. You make a plaster cast of the stump below the knee holding pressure on two points right and left of the patella and your fingers put inwards pressure on the back of the knee . This is called a patella bearing leg .All the weight is taken on the patella. Remove the cast and pour a solid setting mould in the cast and this is a copy of the stump you are working on . Lay up a thin foam rubber cup over the solid mold . lay up a strong fibreglass cup over that and insert some sort of steel rod with a welded flat top plate . It will hang It takes some practice to get it rightdownwards around which the artificial leg will be attached.

It takes some practice to get it right and he will be sore at first and will shrink quickly so he will probably need one again in 6 months and again in 12 months , then he should get 4 or 5 years at least. He should wear a finely knitted sock which can be bought quite cheaply and change and wash it daily. The stump must be washed daily also or infections and fungal agents can get started and cause havock.

People with 4 inch stumps fight in full contact karate competitions and cage fighting so this is still possible for him . The leg must fit well. If a 3D printer can help with any of this good stuff but frankly I doubt it..

johnywelly1 year ago
Hi recently had same problem after my amputation. I used women's breast fillets that go in a bra. It sounds a bit daft but the problem is caused from pistoning of the residual stump into the prosthetic, the chicken fillets are made from a soft silicone material which acts as a buffer. It not a perfect solution but it does help until the end of the stump toughens up
Hope this helps Johnywelly
crazypj1 year ago
Just my opinion but at last people are doing something really worthwhile with a 3D printer.
There's a good chance plenty more is being done but it isn't known about. I don't have an I-Phone so don't need yet another bumper case or plastic model from some video game.
The guy who's making robo-hands for kids is also really amazing
ollo231 year ago
Did you hear about The PCast technic? http://themelbourneengineer.eng.unimelb.edu.au/2010/10/low-cost-artificial-limbs-using-the-pressure-cast-technique/ it seems quite relevant to what you are trying to do! Keep us posted
iamaqtpoo1 year ago
You have a great heart. Have you thought of contacting some of the schools of Orthotists & Prosthetists? Maybe the students could help you as a form of practice? Just a thought. I have attached a few lists for you :)

http://www.ncope.org/info_students/schools.asp
http://www.oandp.org/
http://www.aopanet.org/
paganwonder2 years ago
Thank you for taking Instructables to the next level...I'm sorry I don't have anything helpful to add...Peace be with you all
He is blessed to have you for a cousin! I wish I knew more about prosthetics. Keep thinking. A nurse friend of mine that I work with frequently modifies his braces etc, and helped me modify a wrist brace for carpel tunnel. You gotta do what you gotta do. I say go forward carefully, but if the brace seems strong enough, and you know about drilling holes in metal, go ahead & try bolting it to the brace. It makes sense what you are reasoning that the weight would be further distributed if you can do that.
best to you!
Janice
sunshiine2 years ago
It is interesting that you posted this. I have been wondering how the Blade Runner and others avoid pain while running. He obviously can afford the best! http://www.scpr.org/news/2012/08/03/33622/look-socal-prosthetics-give-athletes-olympic-chanc/

I don't know much about this subject but was thinking (perhaps in ignorance) if the prosthetic was filled with something soft it might distribute the weight of the stump so it is more comfortable. It might also reduce the tendency to favor the good limb. I do hope you can find a solution so your cousin can be pain free! I wish you the best. Have a splendorous day! sunshiine